The field of this disclosure relates generally to integrated gasification combined-cycle (IGCC) power generation systems, and more specifically to a fuel injector for use with an IGCC power generation system.
Known gasifiers convert a mixture of fuel, air or oxygen, steam, coal, and/or limestone into partially oxidized gas, often referred to as “syngas.” In many known power generation systems, the syngas is supplied to the combustor of a gas turbine engine to power a generator that supplies electrical power to a power grid. In some known power generation systems, exhaust from the gas turbine engine is supplied to a heat recovery steam generator that generates steam for driving a steam turbine, such that power generated by the steam turbine also drives an electrical generator that provides electrical power to the power grid.
The fuel, air or oxygen, steam, and/or limestone are injected into the gasifier from separate sources through a fuel injector that couples the fuel sources to a fuel nozzle. In many known power generation systems, fuel injector nozzles extend partially into the gasifier and are thus subjected to extreme mechanical and/or thermal stresses. Some fuel injector assemblies rely on a cooling channel formed within a fuel injector nozzle tip to direct a flow of cooling fluid through the tip. In addition, a cooling coil may be coupled in flow communication with the nozzle tip to provide the flow of cooling fluid through the cooling channel to enhance cooling of the fuel injector nozzle. However, in at least some nozzles, the transition between the fuel injector tip and the cooling coil may be prone to failure when exposed to the extreme mechanical and thermal stresses produced within the gasifier.